Hydraulic well pump



jana 2g 395g E. J. SARGENT HYDRAULIC WELL PUMP 5 Sheets-Sheet 1 Filed Nov. 30, 1953 Jam, 2%9 51953 E. J. SARGENT ZZLM HYDRAULIC WELL PUMP E. J. SARGENT HYDRAULIC WELL PUMP Jan. 2g, @5S

5 Shees-Sheet 5 Filed Nov. 50, 1955 Jam, 2%, E953 E. J. SARGENT HYDRAULIC WELL PUMP 5 Sheets-Sheet 4 Filed NOV. 3Q, 1953 `INVENTOR. TQ/5019,90 d. WEGE/V7 5am. 28, 3958 E. J. SARGENT SZLM HYDRAULIC WELL PUMP Filed Nov. 30, 1953 5 Sheets-Sheet 5 IOOa.-

50M/@Q0 d 67996502;

INVENTOIL Uid rates Patent FO HYDRAULIC WELL PUMP Edward J. Sargent, Los Angeles, Calif., assignor to Sargent Rodless Pump Company, a corporation of California This invention relates to well pump devices and it is particularly directed to improvements in hydraulic motors adapted to be positioned in a well bore to operate a reciprocating pump. This invention is a continuation-inpart of Serial No. 150,208, led March 17, 1950 for a Fluid Motor for Well Pump, now abandoned.

Hydraulically operated deep well pumps have been used with some success, but conventional types of such devices have been made of a large number of complicated parts requiring extremely close tolerances in manufacture. It is an important object of this invention to provide a hydraulically operated motor for a deep well pump, the motor being of simplified construction and employing many standard pump parts and being capable of operation with convention typereciprocating well pumps.

Another object is to provide an hydraulically operated motor of this type employing a plunger member reciprocable in a relatively stationary barrel, the plunger member having an upward tubular extension forming a sliding seal with respect to the barrel so that the plunger member and extension function as a diierential piston, together with a valve assembly on the plunger member arranged to alternately pressurize and vent the chamber formed within the barrel below the said plunger member.

Another object of the present invention is to provide such a hydraulic motor for a well pump having a relatively short and simplied form of valve assembly for controlling operation of the motor.

Another object is to provide a valve assembly of this type having a main valve member of the differential piston type and a pilot valve member of the differential piston type, together with suitable passage means in an enclosing housing so that each of the members is positively held in each of two positions by pressure fluid.

Other objects and advantages will be apparent hereinafter.

ln the drawings:

Figures la, 1b, and lc, show a transverse sectional view of a preferred embodiment of my invention, the gures being separated into three portions because the length of the assembly is too long to be conveniently shown intact. Figure lb comprises an extension of the lower end of Figure la, and Figure lc, is an extension of the lower end of Figure 1b.

Figure 2 is a transverse sectional view taken substantially along the lines 2 2 of Figure lb.

Figure 3 is an enlarged sectional view of the valve assembly taken along the lines 3 3 of Figure 2.

Figure 4 is a view similar to Figure 3 showing the valve parts in another position and taken along the lines 4 4 of Figure 2.

Figures 5, 6, 7, 8, and 9, are transverse sectional views taken respectively along the lines 5 5, 6 6, 7 7, 8 8, and 9 9, of Figure 4.

Figures 10 and 11 are diagrammatic sectional views Showing operation of the fluid motor and pump.

"ice

Figure 12 is a sectional View similar to Figure 3 and showing a modified form of my invention.

Figure 13 is a sectional view similar to Figure 1c showing a further modilication of my invention.

Figure 14 is a transverse sectional view taken substantially on the lines 14-14 as shown in Figure 13.

Referring to the drawings:

A casing 10 extends into the well bore and an eduction tubing 12 extends within the casing 10 and carries a well pump assembly 13 of conventional type at its lower end. The well pump assembly 13 may rest on the shoe 11. A hydraulically operated motor generally designated 14 is provided for operating the pump assembly 13. The motor 14 is carried on the lower end of a motive fluid supply conduit 15, known in the art as macaroni The fluid motor 14 with the well pump 13 at its lower end may be lowered into position within the eduction tubing 12.

The general scheme of operation calls for supplying hydraulic pressure uid to the macaroni 15 to cause the hydraulic motor 14 to reciprocate the lower tube or stem 16,'which projects from the lower end of the motor. This stem 16 is connected to operate the reciprocable plunger 17 of the well pump 13. The plunger 17 operates within the stationary pump housing 18 in the usual manner, causing well fluid to pass upwardly through the shoe 11 past the standing valve 19 and traveling valve 20, through the ports 21 and 22 into the tubing 12. Motive uid exhausted from the hydraulic motor 14 passes through ports 23 and 22, mixing with the uid produced from the well. Both the well lluid and exhausted hydraulic actuating lluid pass upwardly in the tubing 12 to the surface.

In accordance with my invention a connector collar 24 is supported by threads 25 from the lower end of the macaroni 15. A cylindrical working barrel 26 is connected by threads 27 to the upper collar 24 and the lower end of this barrel is connected by threads 28 to the lower collar 29. A stationary sleeve 30 extends downwardly from the upper collar 24 in coaxial relation with the barrel 26. rl his sleeve 30 is connected by threads 31 to the upper collar 24. At its lower end the sleeve 30 is connected by threads 32 to the stationary abutment piece 33.

An annular reciprocating plunger assembly generally designated 34 forms a duid-tight seal with the inner surface 35 of the barrel 26. 'lhis plunger assembly may be of relatively great length and is preferably formed of a plurality of stacked length sections 36 having a close tit with the barrel surface 35 and held in assembled relation by means of an inner sleeve 37 having nuts 38 and 39 connected to its opposed ends by means of threads 40 and 41, respectively.

The lower nut 39 is provided with threads 42 for connection with the upper end of the connector sleeve 43. The lower end of this sleeve 43 is connected by threads 44 to the upper end of the relatively short valve housing 45. The valve housing 45 in a commercial form of my invention is less than one foot in length, whereas the length of the plunger assembly 34 is four feet or longer, and the barrel 26 may be upwards of ten feet long. A tube 46 is secured to the valve housing 45 by means of threads 47 and extends upwardly to the interior of the abutment piece 33, sleeve 48, upper collar 24 and into the interior of the macaroni 15. A hollow cap 49 may be provided on the upper end of the tube 46. The tube 46 is slidably mounted within the sleeve 48 and has a close tit daerewith. From this description it will be seen that the valve housing 45, plunger assembly 34 and tube 46 are reciprocable as a unit within the stationary barrel 26.

A tube 50 is connected to the valve housing 45 by means of threads 51 and extends downwardly within the stationary barrel 26. Threads 52 connect the member .arsenaal with thehollcw,stem;1 6 4which extendsdownwardly to the close fitting stationary `sleeve 573. The sleeve 53 isI held in position between nuts 54 and 55, which are connected to the tube 56 by means of threads 57 and 58, respectively. The vlower nut;is connected by threads 59 to the sleeve 60, which-is in-,turn supportedibythreadse. 61 from thelowerend ofthe lower. col1ar29.- Reciprocation of the valve housing Iv45 within'.thebarrel26.causes... the stem 16 to reciprocate in .thesealing sleeve 53... At its lower end the stem is threadedlymconn'ected.tocollar-.l 62, which in turn is connected to thecros.s.ov,er.collar63, which vis .provided wit-h,` the `ports .21 and 23, previously described.. Reciprocation of .the :Stem 1'6.;causes.. the pump plunger17 to move Aunder its'operativeGylfatwihillw the pumpbarrel 18. 15 The. plungerV assembly 34 .cooperateswth.tirezbarrel 26 Yto provide an upper chamber 6,4 and la lower. chamber. 65. Thefunc'tion .of the valve assembly;,generally,dgt4v nated 66is to. direct ow of motive fluid. from the maca?. roni l5 to' theichamberysfand,alternately, ton/ent saidLtZO chamber to the interior. of` `theztubing ,10,1 toicauseftthe.- plunger assembly y34 and valve assembly .66.10. recipro cate within'thebarrel26., l

The Space 6'7f'a`tj the' upperendbf the valve. h'usingi... 45 and withinthe connector sleeve 43communicatesavith'-Z and formsV a partn of Ythe-chamber 64. Thecornmunic.; tion is established through.- the central openingllt ,in-th connector sleeve 48 "and Withiutheannular,sPCe between thesleeve's7 and 30; A

Wlren pressnre iiuid. is directed'into the.chambe're'.V .30' the-'plunger .assembly 34 v.and `valve. assembly.Y 6.6.1.'arl-fv. caused tomove upwardly'withinthe barrel 26 Wlie'rithe'i; valve assembly. 6,6` cuts ol fthe" fi'jo'w.y Aofi pressure if '1o.'. the. ,chamber 6 5, thelpressurie' ,of actuating. iiuid acting on the-crossvfsectional 'area of'fthejtube46,lcausesgth.;...35" plunger. assembly 34""an'd valve a'ssernblyletojnoye-' downwardly. Thefliftin'g forc'ej'on th' lstern 16 islrelatively great because it 'is developed byv the Vpressure ofthe. motive fluidacting overtherelatievlyilarge electiy area of the annularplun'ger assembly34, 'minusrthe' relativelyA small effective area of the tube 46.' Onthe" o'th'e'rhandl.' the downward force applied to the stem` 1,6 'isV relatively.'- small because it is developed by the pressure vof the motive/jA uid acting only on the relatively'smallecctivearea... of the tube 46.V The result is`that arelatively'large force 45 is availableto lift'the pump plunger'17`while`a relatii/,elyV small force returns it to lower position: This is .an'ideal.;. condition of operation offtheconventional ,recipioatn-'gsil pump13."

The valve assemblyfor directing.' actuating. lidlter-f: v5U" natel'y'into the chambers 64' and'65 isfshownclearljinff. FiguresV 3 andV 4. A central bo're1,701"isr1formed*iiri .thefzs housing45 andethe'upperjend of tlgtisbore,is "propQrtioned: toreceive the enlarged head71"of The valve element72f3. A downwardly .projecting stem: 73A on@ the` valveelement' 55"' 72' engages the upper endrjof'thevarlyeeleinentA 7,4.Y The valve element 74 is providedwithfa-,head ,75. which isf. slidably received within the bore76i`nthe valvehousing: 45; A downwardly projecting stern 77 orrthe valve ele-.- ment 74 is adapted to engageE theupper end '78 .ofLthe-...GU tubular membe1150z" The valve elements. 72,.and 74 Ops... eratelas a unit, and the reason for constructing. themias'.-. separateparts Ais to enablejthe' head vportions..71..and-75v to lfit theirvrespective bores`70"and`f76 with greattac curalcy; even thoughmthebores mayl not be preciselycoaxla A central enlargement79` in the' b0re,70 communicates bygradiajlports l80'vvithr theup'per-Y end'joffthe pair o'fzpassageways 28,1? which 'extend longitudinally/ foffthe. valve-...

housing 45'and'communicate With- 'the chamber-65,. A11-,J7OL

enlargement 82 at thelower end of..the..bor,e../'.0.comiz-v municates by `lateral'ports 83"with the second pairfof. longitudinally extending passageways 8 4.A The-passage? i ways 84 communicate at .th'neirjupperends with ,thezspace 4. The 'ports scommunicate with" an annular' `groovel 86, whichmin turnis in communication withthe lateral ports .4 87 formed in the tubular member 50. Sealing rings 88 positioned on the tubular member 50 above and below the annular groove 86 prevent leakage. It will be seen that the space 67, and hence the chamber 64, is in constant communication with the interior of the tubing 12 through passageways 84, ports ar|d-87;'bore 89 in the tubular member 50, boref90-in -.the.:stem*.:16,I collarf62, cross-over collar 63, port 23V and'port 22 in the pump barrehsupport-. tube91z`;

Afpilot valvef92'hving-anioveralllengtl "gre'aterithn the length of the housing 45 is positioned for axial sliding movementu'n the; housing; 4,5.; relatively/.smallebore 93 in the housingreceives the upper endl 9,4 of the valve 92while spaced portionsa95-of al'larger bore receive the enlarged heads 96 and 97. Lateral ports 98 in the housing 45 establishes communication between the annular groov e\99 andthe upper-.endet thebore -70and thee-an"- nularspace-100 betweenthebore 95 and therecessed ypor-zv tion 101` lof vthe .valve92. Asecond lateral port 102 .inii the housing45 ,leadsfrom .the .annular groove-103 to the f space 104-blowthehead 75 of thefmain valve element 754.-.. A' third laterali port.. 1.05 .communicates .betweenf the. Saninular. Agllfgovef.' 106 aroundv thelpilot .valve and the :annular groei/68.6.adjcentathegports 87. A. With Athe .parts in ,posi-.fVV tion fasi-shown fin" Firgurelfmotive, huid. lunderpressure isi; adrnitt'edito. .the Lin't'eriorofhe tuber46, `passes .to bore;-70 anidoutto, port 80iandto.the:pssagewayf81..4 The-chamber: 65,.v is thus.:pressurized causingthe plunger assernblyfA-z` aridfval"\ /'e assembly.` .66. .to-.mover upwardly relative toi thef-gf stationary .bi'l1=rel2`6. The pilotavalve 92 remains `in there' upper positionbecausefthepressure.on the relativelyglargejf areaof, the v,lwenencl 107.` maintains .it in vthatposition. When thei plunger-.assemblyf34r approachestthe upper endofffit's` .travelfthebumperringY .109 engages the' lower: end'A 1I0'of the" abutment. `piecelll.; The bumper ring.; 109 islslidablymounted .within...thes bore1 12A of the. con-V Hector sleeve .43. and,4 therefore, the `plunger' assembly 34,

connectorsleeve 43 and..valve assembly 66 may..cont,inue:.f. upward "asa .unit...until the. upper-.end v 108 of` the'f.g.pilotf valve 92 causes.tlie..bumper ringgl09 to; engage the ende. 11,0 ofthe abutmentpiece 111... At such time theengage;

mentof the.bumper.ring.109 with the upper endv ofthe,"- pilotvalv. 92- effects 'shiftingeef vthe `pilot valve 92 -to the. position shown in Figure 4. Pressure uid in thetube46.` then V.passes through lateral .port 98, .VarvlnularV space: 110,0,

lateral port. 1,02, .and.into-the.space 104. This high pres# if sui-eA liuidltliengcauses; th'e...main..valve 72-..-74 tomove:

tweenj-lie.valve parts.i72"and .74A is.vented.to` the lower.. pressure 'space throughl ports `83.` and. passageway. 84; and because the .cross sectional .area v.offthe'f .valve .headJSy is greaterthan thecorresponding cross sectional area of ther'-Y "valve head 71. The pilot valve 92 stays inthe..position illustrated in Figure 4 vbecause Vthe highfpressure inthe annular^spacelapplies a downward force. on the en. 1arged-head i96= whiclr' is 'greater than the upward Aforce applied-tothesmallerl head 94'. Infthisrespectthe piloti" valve 92 functionslas va; differential piston `assenibly: The spacelabove thepilot valve 92 remains Vat rela-tivelylow i pressure and Vthech'amben 65 .below thevalvefassembly -is connected to the low pressure existing in-bo're 89 "viafe passagwayszfSL .ports'180, bore 70, ports 83,! passageways 84, and ports 85, 87.' Thezhighpressure:motive fluid .1 doesnotenter. theboref70 becausezthe :valve headi71. seals it olii.. Theerelatively'higlnpressurerof the actuatinge2 fluid. then actsfover-the crossrsectional .area rof:;thetube'f46. within` the..sealing.sleeve48 Vtol'movethe:ztubef46f'andi asa; sembly 66 and stem 60 downward relative to thea-station:1z ary., barrel- 26z` Ih-isedownwarch movementccmtirmeslnir-rV til thelowenbumper .ringillfengageefhe eppernellsre of the lower collar 29. The lower bumperd'ing .11-4`sprovided withf-lugs 116-which1overlie ,thegrupperfende'lji ward movement of the lower bumper ring 114 is arrested by the collar 29, it acts on the lower end 107 of the pilot valve to hold it stationary while the housing 45 continues its downward movement, thus shifting the pilot valve 92 back to the position shown in Figure 3. The main valve parts 72, 74 move downwardly to the position shown since the lower bore 76 is no longer in communication with the high pressure motive fluid. The plunger assembly 34 again moves upwardly and the cycle repeats. It will be observed that the tube 46 constitutes in effect an upward extension of the annular plunger assembly 34, and hence the tube 46 and plunger assembly 34 function as a differential piston. When pressure is applied below this piston by introducing motive fluid into the lower chamber 65 this differential piston generally designated 125 is raised within the barrel 26. When the valve assembly 66 vents the lower chamber 65 to the low pressure conduits the pressure in the upper and lower chambers 64 and 65 respectively both contain liuid at relatively low pressure, and consequently the pressure of the motive fluid acting on the extension 46 drives the plunger assembly 34 downwardly within the barrel 26. Means are provided for cushioning the plunger assembly 34 in the ends of its stroke, and this means preferably takes the form of dashpot mechanisms having one element associated with the plunger assembly 34 and another element associated with the barrel 26. As shown in Figure la, the upper collar 24 is provided with a bore 117 which closely conforms to the tapered surface 118 on the hollow cap 49. When the plunger assembly 34 approaches the lower end of its stroke the uid trapped in the bore 117 by the cap 49 is caused to move outward under high velocity past the tapered surface 118, thereby cushioning the downstroke of the plunger assembly 34. The upper stroke is similarly cushioned by movement of the connector sleeve 43 and its bore 68 upward with respect to the outer tapered surface 119 on the abutment piece 33. Fluid trapped within the annular space 64 is caused to pass outwardly under a high velocity between the taper surface 119 and the surface 120 on the abutment piece 43.

The well fluid produced from the conventional well pump 13 passes upward to the port 21 in the cross-over collar 63. It will be observed that the outlet from this port 21 is positioned above the location of the outlet from the port 23. This construction insures that a jet of exhaust pressure fluid is directed against the upper end of the barrel 18 below the location of the outlet for well fluid into the housing 91. The relatively clean exhaust fluid from port 23 prevents accumulation of sand or other foreign matter at the upper end of the pump plunger.

Sometimes the operation of the pump has been hampered by tendency to stop or hesitate at the lower end of the stroke. This has been found to occur when the pilot valve failed to remain in its uppermost position, and instead moved down to shift the porting to cause the main valve to shift and thereby reverse the direction of motion of the motor piston. It was found that failure of the traveling valve in the production pump to seat properly at the beginning of the upstroke resulted in failure to pick up the load of production fluid above the pump plunger. This in turn was reflected in an unusually low pressure within the annular space 65 below the motor piston or plunger assembly 34. Since the pressure in this space 65 was relied upon to hold the pilot valve 92 in its uppermost position against the normally small force applied to the pilot valve in the annular space 100, a reduction of pressure in the space 65 permitted the pressure in the annular space 100 to overbalance the forces acting on the pilot valve 92 and to move it down to its lowermost position. The entire pump assembly consequently reversed direction of movement. The phenomenon repeated so long as the traveling valve in the production pump .failed to seat properly, with the result that the pump 6 parts moved back and forth over a short stroke in the region of the lower end of the stroke of the pump.

The modified form of pilot valve and porting arrange- VAment shown in Figure l2 has been found to overcome this difficulty. The porting is changed to the annular space a so that no pressure from the macaroni string 15 is admitted to this space 100a at any time. The resultant endwise force on the shoulder tending to `move the pilot valve 92a downward is thus eliminated.

motor plunger assembly 34 reaches the upper end of its stroke the pilot valve 92a engages the ring 109er and is thereby mechanically shifted to its lower position. In such lower position the sealing portion 132 seals within the bore 93a to cut off communication between the space 100tz and the space 67a. At the same time the necessary force required to hold the pilot valve 92 in its lower position is developed by motive uid pressure from the macaroni 15 passing through port 133 and port 131 to annular space 100a. The pilot valve 92a may be provided with a helical relief passage 134 between the sealing parts 94a and 132.

Another difficulty has been encountered in the operation of the device which Vwas manifested by short stroking at the upper end of the pump stroke. It has been found that this was caused by over pumping the well, that is, by withdrawing the well uid faster than the rate at which it flowed into the well, or by operation of the pump in a well having a very large proportion of gas to oil. [n such case, gas rather than liquid filled at least a part of the space between the traveling valve 20 and the standing valve 19 in the production pump. When the direction of motion reversed at the top of the stroke, the weight of the column of production fluid within the tubing 12 above the traveling valve 20 applied a very large downward force to the entire moving assembly of the pump. This force of large magnitude was resisted only by the relatively small force of compression of the gas in the space above the standing valve 19. As a result the pump plunger 17 and motorplunger assembly 34 and associated parts are propelled downward very rapidly. The absence of liquid below the pump plunger 17 in effect exerted a downward force on the pump plunger 17 and motor plunger assembly 34. The downward movement of these two plungers then occurred so rapidly that motive uid could not be exhausted from annular space 65 as rapidly as required. Back pressure then developed in the annular space 65 and this back pressure acting on the lower face of the pilot valve 92 moved it upward prematurely. The lower exposed face 107 of the pilot valve 92 is sufficiently great in area to overbalance the force applied in the annular space 100:1 even though the latter may have higher pressure intensity.

This diiculty of short stroking at the lower end of the stroke is overcome by means of the modified form of the apparatus as shown in Figures 13 and 14. A series of check Valves are installed in the outlet ports 22a which carry well iiuid from the production pump into the tubing 12. The function of the check valves 140 is to permit well uid to be produced through them in an upward direction into the tubing 12 but to prevent reverse flow from the tubing into the production pump. At the upper end of the stroke of the pump plunger 17a the valves 140 close and thereby prevent application of heavy downward forces by the fluid column in the tubing 12 to the production pump plunger 17a. The moving parts of the uid motor and pump then move. downward to compress the gas labove the 'standingvalvev 19 but the heavy torce .caused-bit thelYSIu-HQ headn th -mbipgef nis-eliminate C heels .yelvesfzgeuerallvdesignatedi.1401includeiballs" 141adapted'lto tclose against upwardly facin'g seats 142 PrQYdedOu thestaouery'part 143.' Any-.suitable means 5 assemblvandnrojectingdownwardly;therefmm for npsuchfas;fonexampleg'the transverse pins, 144`maybe providedforjlimiting upward movement of 'the ba'lls"141`;

Havinghfullyidescribedmy invention,.it is to be understoodethatldo `not'wishjto be limited to .the details herein set'forth;jbut1my inventionY isA of .the. full.v scope.. of the' appended claims. 1

I. claimt;

1. In ya reciprocatingjuid motor-driven,` deep well a pump 'assernblyladapted ",toibelowered into an'4 eduction tubinff on the lower 'endj'of motive ,fluide supplycon. duttheeumbuaiou of'aludmotor having a .recitulo-A cating @part driven by pressureofgmotiveuid 'supplied through saidiconduit,Y tlrejmotor.-also halvingI/a tube de-` pendingvfromsaid .reciprocating partand carrying eX-, 1131151; uids from the motor, a.-pumP.-.12Qsitioued belowA the'motorjand havingja reciprocating tube carrying fluid produced:from thewell, fa member connecting said'tubes togetlienjtheV member havinggpQrtsfrespectively connected` toi'said tubes ,andlarra'ngedto direct the/exhaust 'huid fromj'the'motor tube outwardly Iatja low elevation. and'4 tofdirectithe' well .tlui'd` fromu theN pu n1p tube.outwardly Y at 'La *high' elevation.

2:In"a reciprocating ilui'd'motonfor operationV ofia Well pump, lthe combination of:Y a stationary barrel adapted including' a' plunger, theplunger irbe'ingA mounted to reciprocate'in: said barren; 'said.""assemb'ly nhaving axially I extending tube's xedwith relation. thereto .and extending, above .and Vhelowtheplunger,` upper rand lower. stationary sleevesencircling'hthe tubes forming@ slidingv seals be- 3 andthe. tube in telescopic Vrelatio1`1, said unitary assemblyy 40 including a valve.,assemblyfsecured. thereto andlhaving rs'tepassagejmeans establishing, communication between the/upper tube andsadlOWerchambei'., a valve onthe valve assemblymovable to'close theiirsft said passage means;the valve assembly having a second passage means establishing constant communication between said Vlower tubfand' said upper chamber.

3; Inia reciprocating -fluidjmotor for operation `of a well pump, the combination of a stationarybarreladapted. to "bepositioned in a. well boreba unitary assembly` including'an annularplunger reciprocable insaid barrel, saidl assembly, having axially extendingtubes xed with relation Vthereto and extending.. above and below 'the plunger;V .sealing means including stationary sleeves encircling .the Atubespto form slidingseals between each. ofi, the-'tubesand the barrel,1the upper sleeve lextendingbetweentheplungerand uppertube yin telescopic relation, theysealing means, `plunger and barrel cooperating to v forma lrst chamberjwithin the. barrel above the plunger anda second chamber within the barrel. below vthe plunger; a valve assembly Vsecured to' the plunger and having' first-passage means establishingl communication'AV between the upper-tube and the -lower chamber, a gvalve on'the valve assemblyrnovable to close said rstpassage f *J valve ANin said 'va-lvehousilgfgn for controlling 'movement' means, the valve assembly having a second passage means establishing'. constant YVconufnunication between the lower tube: andfthe' upper .chamberf 4.-In a reciprocating uidzmotor. ad'iptedtov be .low-A eredinto arl-eductiontubing on thealower end .of a: motive uidi supply-.conduit .into `position for operating a .driveni 70- mechanism such. asa-welLpumpfg-ithe combinationofta banrelameansifor.,securing.theebarrel relative ,to the-mo.- tivefuid .supply conduit, ananuular. .plunger Areciprocable in said; barrel, A`a ,valve .assemhlysecured relative to. they erating the drivenlmechanism,means forminguppenand,... lower jslidilig, Nsealsglbeftweeneach .of; said l.tubesandsthe barrel; Sadkmeansmtuhes. .and 'valve assemblyidening an.upperichambegwith' y.thela'rrel above, the plunger?.

andlalowenchamber withinithe'barrel.belowthe'plun-ger,.,

the Valve. assemblitlliaving passage. means i. establishing.; commuriicaQilM between :the lippen tube". .and they lower.. 1. chamb.elr.,. .a valvefron ..the}.valve.f. assembly; movabl'estql Close.. saidjvv uassage -means...and;i11eans,..estab1ishing con-` 15e stanti Communication.. betn/.eena..the....lower tube;` and...the,.

upper chambert..

5,. j In` a. recipiroeeltiigc flujid Amotor for.l operation ..of..'ai welljpump, thlcombinan nofja. stationary vbarrel,adapted.;1y to be. positionedina. We1l.fbore,a..plunger. assembly inf;

Cludng eulanuular plunger. reciprocable in' said Vb21rre.l, .l.

a valve housing secured jtojtheplilnger and movablethere:..-V with, amotive fluid deliverytube', fixedv to .thevalve hous-.; ing-aud Projecting. througaitheauuular plunger., means-fcooperating with th plunger andlbarreltofornl anuppeuf.' A, five .theplunger and a lower-.; charrlbe'r` within; the; barrelbeloyv. the ,-plunger., the ...valve housin/gjhavingta passage restabliislin`g communication be,... tweenthejmotive fluid' delivervtube and .the .lowers chamberge .valve ,inftlijel ve'housing movable tolcloses-saidl ..1 itig, a secondpassage establishe.:` ingjconstantcommunic ionbetween th'e'uppen chambers and.A Space uutsdebctlrlsaidchatnbers.

V6.. fln" a reciprocatin' ,iui'd fjmotor for; .operation fof.l fa... wellzpumglhe,combinationof astationarybarrel adapted...

. to :be positioned V'inea rwell. bore-1.a. relatively` long. annular;-

plunger,,reciprociable,Y in Y saidi barrel, 'a relatively.. .short... valve housing. ^securedlto,thellower. endj of the.plunger.... and movabletherewith@.mfvejuidi deliveryube tired;` l to the jvalveihoiusingand projecting; through the. annulan. .plunger above the. 'barrel`mean.s; cooperating. with the.-.. plunger and barrel'to form an upper chamberfwithinthe... barrelY above theA plungerand a lower chamberwithin the barrel'below the.pl unger,the .valve housing having. a passage establishing communication between the motive iluidideliveryT tubefudlh'e lower chamber, a valve in the valve'housingrnovable 'toclose said passage, meansf. Y

providing a 'sc condpassage establishing. constantv com.. municationj between the topper, chamber, and space. out-V side. botlr'saidl chamber s`and means to deliver. motive. fluid under pressure intosaid'tube.

7;Inv a reciprocating fiuid motor for operation .of-,.a. Well pump',gthel combination of; a stationary. barrel adapted to 'be positioned in a well bore, anv annular plunger.

reciprocableY in jsaidibarrel, a .valvehousing Asecured .to

the," 10u/.er eudgf. .thelgnlunger movable therewith am tube fired? 'to'.tuevalve; ihousin and.` :eXtendinaaxiHr through the plungergsealing meansincluding a` stationary.,` sleeve. enildllgflhe lube 'rm a. Sliding `seal .beta/.eener thegtubeaudhebar. 1.,.,th.e-sleeve,extendingwithlnihe... plungerj'in.teleseunief,re1'atieu,.:the;valve-thawing.haring-; passagemeeusiestablishiua communication. between saic'Li. tube an'l` a lowerclramber -defined; withinjhe brlel belowf. the" plunger,l j a"valve"1member in the valve. housingw moy# able to-closesaidgf-passage'means,V means including a pilot.

of `the valve member between open-*and closede positions; the: saidlsleeve'haivinglabutm entifme ans tth ereon operative' to :electfshifting ofiftheupilotevalve* relative toA the --valve--j housingiatdirentrperlzendiofethe; strokeY offtheplungen 801.11 feel-allocating .ruitrmotor fforeoperation zofaze Weilf um c$l3mbH3iOn1fQfti ara-,Stationary :baZrrelc-'-v adapte fue beeaeeitiouecleina Wegener-.eeaerelativelyelong;f; annuler'apluugeweiareeebe .meut-barrel). wel tivelye short. .valve housing Csecured..to. theelower-'end-...oiathefj housing 'and extending axially through the plunger, sealing means including a stationary sleeve encircling the tube to form a sliding seal between the tube and the barrel, the sleeve extending within the plunger in telescopic relation, the valve housing having passage means establishing communication between said tube and the space within the barrel below the plunger, a valve member in the valve housing movable to close said passage means, means including an axially shiftable pilot valve in said valve housing for controlling movement of the valve member between open and closed positions, the said sleeve having abutment means thereon operative to elect shifting of the pilot valve relative to the valve housing at the upper end of the stroke of the plunger.

9. In a reciprocating lluid motor for operation of a Well pump, the combination of a stationary barrel adapted to be positioned in a well bore, a relatively long annular plunger reciprocable in said barrel, a relatively short valve housing secured relative to the plunger assembly and movable therewith, a tube xed to the valve housing and extending axially through the plunger, sealing means including a stationary sleeve encircling the tube to form a sliding seal between the tube and the barrel, the sleeve extending within the lplunger in telescopic relation, the valve housing having passage means establishing communication between said tube and the space within the barrel below the plunger, a valve member in the valve housing movable to close said passage means, means including a pilot valve in said valve housing for controlling movement of the valve member between open and closed positions, a oating abutment ring within the barrel and positioned below the annular plunger and above the valve housing, the said abutment ring being engageable with said sleeve and said pilot valve to etect shifting of the pilot valve relative to the valve housing at the upper end of the stroke of the plunger.

10. A control valve assembly for a fluid motor having a reciprocating plunger, comprising in combination: a valve housing, means whereby the housing may be secured to the plunger, the housing having an inlet opening for motive fluid at its upper end and an outlet opening for exhaust fluid at its lower end, a valve member comprising two separate contacting parts slidably mounted in axially aligned bores provided in the housing, one of the bores being smaller than the other and being in communication with the inlet opening, the housing having a passage communicating with the small bore and terminating at the lower end of the housing, the first valve part in the small bore being axially movable between an open position permitting ow from the inlet opening Ithrough the first passage, and a closed position preventing such ow, an axially shiftable pilot valve in said housing, and port means in the housing whereby the pilot valve may place the inlet opening in communication with the larger bore below the second valve part.

1l. A control valve assembly for a uid motor having a plunger, comprising in combination: a valve housing, means whereby the housing may be secured to the plunger, the housing having an inlet opening for motive uid at its upper end, a valve member including t-wo axially spaced portions slidably mounted in axially aligned bores provided in the housing, one of the bores being smaller than the other and being in communication with the inlet opening, an axially shiftable pilot valve in said housing comprising two axially spaced portions slidably mounted in axially aligned bores provided in the housing, one of the bores being smaller than the other, the housing having a port establishing communication between the inlet opening and the larger bore for the pilot valve, the housing having a port establishing communication between -the larger bore for the pilot valve and the larger bore for the valve member, the housing having outlet passage means communicating with the smaller bore for the valve member, said outlet passage means being in communication with the inlet opening when the valve member is shifted in a direction away from the"l inlet opening.

12. A control valve assembly for a uid motor having a plunger, comprising in combination: a valve housing, means whereby the housing may be secured to the plunger, the housing having an inlet opening for motive uid at its upper end, a valve member including two axially spaced portions slidably mounted in axially aligned bores provided in the housing, the upper bores being smaller than the lower and being in communication with the inlet opening, a pilot valve in said housing having an over-all length greater than the length of the housing and being axially shiftable to extend from either end of the housing, the pilot valve comprising two axially spaced portions slidably mounted in axially aligned bores provided in the housing, one of the bores being smaller than the other, the housing having a port establishing communication between the inlet opening and the larger bore for the pilot valve, the housing having a port establishing communication between the larger bore for the pilot valve and the larger bore for the valve member, the housing having outlet passage means communicating with the smaller bore for the valve member, said outlet passage means being in communication with the inlet opening only when the valve member is in its lower position.

13. A control valve assembly for a uid motor having a plunger, comprising in combination: a valve housing, means whereby the housing may be secured to the plunger, the housing having an inlet opening for motive uid at its upper end, a Valve member functioning as a differential piston and including two axially spaced portions slidably mounted in axially aligned bores provided in the housing, the upper bore being smaller than the lower and being in communication with the inlet opening, an axially shiftable pilot valve in said housing comprising two axially spaced portions comprising a differential piston slidably mounted in axially aligned bores provided in the housing, one of the bores being smaller than the other, the housing having a tirst port establishing communication between the inlet opening and the larger bore for the pilot valve between said spaced portions thereof, the housing having a second port establishing communication between the latter said bore and the larger bore for the valve member below the lower portion thereof, the housing having outlet passage means communicating with the smaller bore for the valve member and having additional low pressure passage means, the valve member, pilot valve and housing parts being so proportioned that when the pilot valve is in a rst position pressure uid in the inlet opening passes through the first and second ports to maintain the valve member in a first position wherein it isolates the inlet opening from the outlet passage means, and so that when the pilot valve is in a second position the latter said bore below the valve member is vented to the low pressure passage means through the second port so that the valve member is moved by the pressure of the motive uid in the inlet opening to establish communication from the inlet opening to the outlet passage means.

14. A control valve assembly for a uid motor having a plunger, comprising in combination: a valve housing, means whereby the housing may be secured to the plunger, the housing having an inlet opening for motive lluid at its upper end, a valve member including two axially spaced portions slidably mounted in axially aligned bores provided in the housing and connected by a rst passage, one of the bores being smaller than the other and being in communication with the inlet opening, an axially shiftable pilot valve in said housing comprising two axially spaced portions slidably mounted in axially aligned bores provided in the housing and connected by a second passage, one of the bores being smaller than the other, the housing having a port establishing communication between the inlet opening and said second passage, the housing also having a port establishing communication between said 

